3. Go Redder Like Angelina Jolie

MUST-HAVE KIT Fekkai Salon Color 8R Light Auburn-Eva ($30; ulta.com).PRO TIP The risk for taking brunet hair redder is that purple undertones can appear. To avoid this, “go for shades that are more copper and gold,” says Lorri Goddard-Clark, a colorist at the Neil George Salon in Los Angeles. “You’ll get the fiery effect without any berrylike tint.”

5. Go Darker Like Scarlett Johansson

PRO TIP It’s easy to go too dark, so use one shade lighter than what you think you need (it often comes out darker than what’s shown on the box), says N.Y.C. colorist Sharon Dorram. As color fades with shampooing, it will look more natural anyway.

9. Go Redder Like Rihanna

PRO TIP Fragile or chemically straightened hair calls for a gentle formula, like a semipermanent color that contains no ammonia or peroxide. For extra protection, do a deep-conditioning treatment before applying the formula.

12. Go Redder Like Nicole Kidman

MUST-HAVE KIT L'Oreal Paris Feria 74 Copper Shimmer ($10; drugstore.com).PRO TIP For redheads wanting to go even redder, a kit with several different shades of the same hue will create the most natural-looking results. Multitonal kits (like Feria) give this kind of dimension but are still a one-step process, says Kyle White.